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expand.h revision 1.1.1.2 
      1 /*
      2  * Expanding strings
      3  */
      4 /* $Id: expand.h,v 1.1.1.2 1999/10/20 14:27:31 hubertf Exp $ */
      5 
      6 #define X_EXTRA		8	/* this many extra bytes in X string */
      7 
      8 #if 0				/* Usage */
      9 	XString xs;
     10 	char *xp;
     11 
     12 	Xinit(xs, xp, 128, ATEMP); /* allocate initial string */
     13 	while ((c = generate()) {
     14 		Xcheck(xs, xp);	/* expand string if neccessary */
     15 		Xput(xs, xp, c); /* add character */
     16 	}
     17 	return Xclose(xs, xp);	/* resize string */
     18 /*
     19  * NOTE:
     20  *     The Xcheck and Xinit macros have a magic + X_EXTRA in the lengths.
     21  *     This is so that you can put up to X_EXTRA characters in a XString
     22  *     before calling Xcheck. (See yylex in lex.c)
     23  */
     24 #endif /* 0 */
     25 
     26 typedef struct XString {
     27 	char   *end, *beg;	/* end, begin of string */
     28 	size_t	len;		/* length */
     29 	Area	*areap;		/* area to allocate/free from */
     30 } XString;
     31 
     32 typedef char * XStringP;
     33 
     34 /* initialize expandable string */
     35 #define	Xinit(xs, xp, length, area) do { \
     36 			(xs).len = length; \
     37 			(xs).areap = (area); \
     38 			(xs).beg = alloc((xs).len + X_EXTRA, (xs).areap); \
     39 			(xs).end = (xs).beg + (xs).len; \
     40 			xp = (xs).beg; \
     41 		} while (0)
     42 
     43 /* stuff char into string */
     44 #define	Xput(xs, xp, c)	(*xp++ = (c))
     45 
     46 /* check if there are at least n bytes left */
     47 #define	XcheckN(xs, xp, n) do { \
     48 		    int more = ((xp) + (n)) - (xs).end; \
     49 		    if (more > 0) \
     50 			xp = Xcheck_grow_(&xs, xp, more); \
     51 		} while (0)
     52 
     53 /* check for overflow, expand string */
     54 #define Xcheck(xs, xp)	XcheckN(xs, xp, 1)
     55 
     56 /* free string */
     57 #define	Xfree(xs, xp)	afree((void*) (xs).beg, (xs).areap)
     58 
     59 /* close, return string */
     60 #define	Xclose(xs, xp)	(char*) aresize((void*)(xs).beg, \
     61 					(size_t)((xp) - (xs).beg), (xs).areap)
     62 /* begin of string */
     63 #define	Xstring(xs, xp)	((xs).beg)
     64 
     65 #define Xnleft(xs, xp) ((xs).end - (xp))	/* may be less than 0 */
     66 #define	Xlength(xs, xp) ((xp) - (xs).beg)
     67 #define Xsize(xs, xp) ((xs).end - (xs).beg)
     68 #define	Xsavepos(xs, xp) ((xp) - (xs).beg)
     69 #define	Xrestpos(xs, xp, n) ((xs).beg + (n))
     70 
     71 char *	Xcheck_grow_	ARGS((XString *xsp, char *xp, int more));
     72 
     73 /*
     74  * expandable vector of generic pointers
     75  */
     76 
     77 typedef struct XPtrV {
     78 	void  **cur;		/* next avail pointer */
     79 	void  **beg, **end;	/* begin, end of vector */
     80 } XPtrV;
     81 
     82 #define	XPinit(x, n) do { \
     83 			register void **vp__; \
     84 			vp__ = (void**) alloc(sizeofN(void*, n), ATEMP); \
     85 			(x).cur = (x).beg = vp__; \
     86 			(x).end = vp__ + n; \
     87 		    } while (0)
     88 
     89 #define	XPput(x, p) do { \
     90 			if ((x).cur >= (x).end) { \
     91 				int n = XPsize(x); \
     92 				(x).beg = (void**) aresize((void*) (x).beg, \
     93 						   sizeofN(void*, n*2), ATEMP); \
     94 				(x).cur = (x).beg + n; \
     95 				(x).end = (x).cur + n; \
     96 			} \
     97 			*(x).cur++ = (p); \
     98 		} while (0)
     99 
    100 #define	XPptrv(x)	((x).beg)
    101 #define	XPsize(x)	((x).cur - (x).beg)
    102 
    103 #define	XPclose(x)	(void**) aresize((void*)(x).beg, \
    104 					 sizeofN(void*, XPsize(x)), ATEMP)
    105 
    106 #define	XPfree(x)	afree((void*) (x).beg, ATEMP)
    107